Rudder for ships

ABSTRACT

The invention relates to a rudder for ships with propeller drive, in which the propeller is arranged to rotate about a propulsion axis, with a rudder blade ( 15 ) and a flow body ( 20 ) arranged on the rudder blade ( 15 ), whereby the flow body designed in a bulb or zeppelin shape is arranged as an extension of the propulsion axis in the region of the rudder blade and is designed to self-destruct or self-detach in the event of an increase in the effect of force, blow, impact or pressure.

TECHNICAL FIELD

The invention relates to a rudder for ships.

PRIOR ART

Rudders of ships with a propeller drive these days often have aso-called Costa bulb (a stream-lined body of revolution integral with arudder and directly in line with the propeller). The purpose of theso-called Costa bulb or propulsion bulb is that a bulge, which isdesigned to be bulb-shaped or zeppelin-shaped and constitutes a flowbody, is configured as an extension of the propulsion axis in the regionof the rudder blade. The purpose of this flow body is that the overallprofile of the hub is extended to the point where there is only minimalturbulence of the wake.

This type of Costa bulb is known for example from patents DE 198 44 353A1, DE 84 23 818 U and DE 82 24 238 U.

The effect of the Costa bulb is a result of its bead-shapedconfiguration, by which it is distinguished from the rudder orrespectively rudder blade, resulting in favorable flow.

The Costa bulb protrudes laterally relative to the rudder blade and inthe event of an impact, a blow or pressure the Costa Bulb is in theimmediate impact zone. This means that the Costa Bulb would be damagedbefore the actual rudder blade would be damaged.

However, in the event of an impact, a blow or pressure on the prior artCosta bulb the rudder blade would also be affected, because the Costabulb transfers the force acting on it to the rudder blade and there isthus the added danger of damage to the rudder blade.

SUMMARY OF THE INVENTION

The purpose of the invention is to provide a rudder blade for ships,which in spite of favorable flow due to external effects, is lesssusceptible to damage or destruction due to the effect of an impact, ablow or pressure and that the flow body is independently destroyed orself-released in the event of such pressure, blow or impact.

At the same time it is advantageous if the flow body divides the rudderblade, viewed in the vertical direction, into two areas (A, B), wherebyboth areas are designed identically or not identically in profile. Inthis respect it is effective if the longitudinal middle lines of theareas of the rudder blade are not superposed with the middle line of theflow body and respectively form an angle α therewith.

It is also effective if the angle α between the longitudinal middle lineof a region of the rudder blade and the middle lines of the flow bodyare different for both of the areas (A, B).

In terms of the invention it is advantageous if the flow body haspredetermined break-off sites, which lead to the destruction of the flowbody in the event of the increased effect of force, a blow, an impact orpressure on the flow body. At the same time it is a further advantage ifthe predetermined break-off sites are designed as predeterminedbreak-off lines. Also, it is effective if the predetermined break-offlines are oriented in the longitudinal and/or transverse direction ofthe flow body. But it is also advantageous if the predeterminedbreak-off lines are distributed in a reticulated manner over the flowbody.

In terms of the invention it is effective if the predetermined break-offsites or predetermined break-off lines are designed as materialweaknesses, material reductions, shear lines and/or perforations.

In an advantageous embodiment it is effective if the flow body comprisesmetal or a non-metallic material or a metal-non-metal mixture.

In another advantageous embodiment it is effective if the flow bodycomprises a carbon-fiber composite material.

In a further advantageous embodiment it is effective if the material hasembedded carbon fibers, graphite fibers and/or fiberglass.

In yet another advantageous embodiment it is effective if the flow bodycomprises a synthetic material or synthetic materials.

In an advantageous embodiment it is effective if the flow body comprisessynthetic material, such as polyoxymethylene, polyformaldehyde orpolyacetates.

In a particularly advantageous configuration the flow body comprises twoindividual bowl-shaped longitudinal bodies conforming to the flow bodyand held, in longitudinal edge regions, on the outer wall faces of therudder blade via predetermined break-off lines. The edge regions of bothbowl-shaped longitudinal bodies facing the propeller are connected viapredetermined break-off lines to a spherical cap-shaped component, inturn connected solidly or detachably to the rudder blade.

The advantage of the inventive configuration of the flow body of arudder blade of a rudder for ships is that due to the possibility of theflow body being destroyed or self-released while in the event ofpressure, blow or impact effect the rudder is not impaired. There isalso the possibility that conventional rudder blades can be retrofittedwith the inventive flow body.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in greater detail hereinbelow on thebasis of an embodiment by way of the drawings, in which:

FIG. 1 is a diagrammatic view of the stem of a ship with a drivepropeller and the rudder blade of a rudder, whereby the rudder blade isfitted with the inventive bulb-shaped flow body,

FIG. 2 is a diagrammatic view of the rudder blade with a flow bodycomprising three components in the state of destruction in an explodedview,

FIG. 3 is a frontal elevation of the rudder blade with the flow body inthe state of destruction,

FIG. 4 is a diagrammatic view of the rudder blade with the flow body,

FIG. 5 is a rear elevation of the rudder blade with the flow body,

FIG. 6 is a side elevation of the rudder blade with the flow body,

FIG. 7 is a frontal elevation of the rudder blade with the flow body,

FIG. 8 is a plan view from above of the rudder blade with the flow body,and

FIG. 9 is a plan view from below of the rudder blade with the flow body.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows the stem 11 of a ship 10 with a drive propeller 12 and arudder 13, whereof the rudder blade 15 is fitted with a bulb-shaped orzeppelin-shaped flow body 20, preferably designed as a hollow body andwhich can be integrated into the rudder blade 15 and can comprise two ormore components 21, 22, attached to the outer wall faces 15 a, 15 b ofthe rudder blade 15. The flow body 20 can also be designed as a fullbody. In the extension of the propulsion axis a bulge, which forms theflow body 20, also known as propulsion bulb or Costa bulb, is designedin the region of the rudder blade 15. The flow body 20 is designed suchthat in the event of a pressure, blow or impact effect it isself-destroying or self-releasing.

To achieve the possibility of self-destruction, the flow body 20comprises individual wall sections, interconnected via predeterminedbreak-off lines 40 in the form of material weaknesses, materialreductions, shear lines, or perforations. Such break-off lines for usein other fields are generally known to those skilled in the art ofmaterials/design engineering and related fields. Rudders are notmass-produced articles but are rather single-unit productions that areadapted in terms of their dimensions, materials and the like for eachindividual ship. Hence, the specific dimensions and placement ofbreak-off lines will differ for each individual rudder. A person skilledin the art will be able to determine the rated break points for thebreak-off lines 40 and how to configure the same.

Generally, the material weaknesses, material reductions, shear lines orperforations comprise a thinning or reduction in thickness of the wallof the flow body 20 near the points of attachment to the rudder blade 15and/or the other parts of the flow body 20. Preferably, the thinning orreduction in thickness of the wall does not pass completely through thewall of the flow body 20. The predetermined break-off lines 40 arepreferably designed and arranged on the inner surface such that thereare no wrinkles, depressions, grooves, slots or the like in the outersurface of the flow body 20, which is hollow. Thus, the flow body 20 hasa smooth outer surface to reduce drag or turbulence around the flow body20. This is accomplished by arranging the material weaknesses, materialreductions, shear lines or perforations on the inner surface of the flowbody 20.

Preferably, the material weaknesses, material reductions, shear lines orperforations are configured as indentations, depressions, notches orgrooves in the thickness of the material from the inside-out, withoutpassing completely through the wall of the flow body 20. Theindentations, depressions, notches or grooves, i.e., reductions inthickness, of the wall are configured such that a pre-determinedthickness of material remains on the outer surface of the flow body 20on top of the indentations, depressions, notches or grooves. Ideally,the indentations, depressions, notches or grooves would reduce thethickness of the wall of the flow body 20, by anywhere from 1% to 99%,keeping in mind that enough material must remain to support structuralintegrity of the flow body 20.

These material weaknesses, material reductions, shear lines orperforations are configured such that the flow body 20 maintainsstructural integrity under pre-determined normal operating forceconditions, i.e., stresses. In the event of a blow, an impact orpressure on the flow body 20 in excess of the pre-determined normaloperating force conditions, the material weaknesses, materialreductions, shear lines or perforations are configured to losestructural integrity such that the flow body 20 separates from therudder 15. Normal operating conditions will vary from ship-to-ship,depending upon the size of the vessel, the force from the wake of thepropeller, and the configuration of the rudder 15, among other factors.A person skilled in the art knows how to calculate force vectors andloads on the flow body 20 to determine the required dimensions orthickness of material to maintain structural integrity under normaloperating conditions and lose structural integrity when normal operatingconditions are exceeded, which dimensions will vary from ship-to-shipbased upon the particular rudder design.

The material weaknesses, material reductions, shear lines orperforations may comprise continuous indentations, depressions, notchesor grooves in the material or be discontinuous, i.e., dashed orinterrupted. The predetermined break-off lines 40 may be configured in alongitudinal direction and/or run transversely to the longitudinaldirection of the flow body 20. The predetermined break-off lines 40 mayalso be irregular in their placement on the flow body 20 or distributedin a reticulated manner over the flow body 20. In a preferredembodiment, the break-off lines 40 are disposed adjacent to the edges ofthe flow body 20 where it is attached to the rudder 15, as depicted inFIGS. 2, 4 and 6. In this configuration, a blow, an impact or pressurein excess of the pre-determined normal operating conditions will causethe flow body 20 to separate from the rudder 15 at the break-off lines40 so as to leave as little material as possible on the rudder 15.

An essential element of the inventive design of the rudder blade 15 isthat the flow body 20 self-destroys or detaches in the event of theeffect of an impact, a blow or pressure. The self-destruction ordetachment occurs at the point of the material weaknesses, materialreductions, shear lines or perforations forming the break-off lines 40.This ensures that no excessive force is transferred through the flowbody 20 to the rudder blade 15 itself so that any impairment to therudder blade 15 resulting from substantial damage or destruction can beprevented.

FIG. 2 shows the view of a rudder blade 15 having a flow body 20, madeup of three individual parts 50, 51, 55. Here the parts 50, 51 form thesides of the flow body 20 on the sides of the rudder blade 15 and thepart 55 forms the front, i.e. the substantially somewhat hemisphericalend section facing the propeller 12. Arrows X, X1, X2 indicate that theparts 50, 51, 55 in these directions are disassembled from the rudderblade 15. Typically, the parts 50, 51, 55 of the flow body 20 arebowl-shaped and preferably form no solid bodies, rather just form ahollow body in the assembled state, built onto the rudder blade 15.

Then the flow body 20 comprises two individual bowl-shaped longitudinalbodies 50, 51, conforming to the flow body, which in the region of theirlongitudinal edges 50 a, 51 a are held via predetermined break-off lines40 on the outer wall faces 15 a, 15 b of the rudder blade 15. The edgeregions 50 a, 51 b of both bowl-shaped longitudinal bodies 50, 51 facingthe propeller 12 are connected via predetermined break-off lines 40 to aspherical cap-shaped component, connected solidly or detachably to therudder blade 15 (FIGS. 2 and 3).

It is further evident from FIG. 2 that the rudder blade 15 is not ahomogeneous component, but rather is formed from an upper area A and alower area B. The upper area A has at least on its front side a curve orcut, which is bent or oriented more to the left, and the lower area Bhas at least one curve or cut, which is bent or oriented more to theright. At the interface of both areas A and B this difference is evidentfrom the fact that both front areas are designed as tabs, which do notmatch one another congruently, but stand apart from one anotherapproximately y-shaped. The longitudinal middle lines LM1 of both areasA and B are not congruent or parallel. Also, the longitudinal middlelines LM1 of the areas A and B do not lie on the middle line ML of theflow body 20.

FIG. 3 shows a view of the rudder blade 15 with the flow body 20 havingparts 50, 51 and 55. It should be noted that the areas A and B can bedifferent so that the longitudinal middle lines LM1 breach the leadingedge at LM1 and thus lie outside the middle line ML of the flow body 20.In another embodiment of the invention, not illustrated here, the upperarea A can however also be identical to the lower area B, such thateither the deviation of the longitudinal middle line LM1 to the middleline ML of the flow body 20 is the same and different at a zero angle,or can be equal to zero.

FIG. 8 and FIG. 9 in each case show a view of the rudder blade 15 frombelow or respectively from above. Evident in each case is the angle αbetween the longitudinal middle line LM1 of both upper and lower areas(A and B) of the rudder blade 15 and the middle line ML of the flow body20. The angle α (alpha) exists between the longitudinal middle line(LM1) of upper area (A) and the middle line (ML) of the flow body 20.The angle β (beta) exists between the longitudinal middle line (LM1) oflower area (B) and the middle line (ML) of the flow body 20. The anglesα and β may be the same or different.

FIG. 4 shows a rudder blade 15 with a flow body 20 in a side elevationfrom the rear left. Here, the areas A and B are apparent. In the reararea the areas A and B are identical, whereas in the frontal region theyare designed different (see also FIG. 2).

FIG. 5 shows the rudder blade 15 in a view from behind and FIG. 7 showsa frontal view. In each case the flow body 20 can be clearly viewed.

FIG. 6 shows the inventive rudder blade 15 with the flow body 20,whereby the flow body has predetermined break-off sites for betterself-destruction in the event of the effect of an impact or a blow orpressure. The predetermined break-off sites are advantageously providedas predetermined break-off lines 40, and are distributed over thesurface of the flow body—as described above.

As depicted in FIGS. 8 and 9 the rudder blade 15 has a cross-sectionalarea 16, the longitudinal middle line LM1 of which is offset at an angleα to the middle line ML of the flow body 20, so that the leading edgestringer strip 70 of the rudder blade 15 facing the drive propeller 12is not aligned with the middle line ML of the flow body 20.

The flow body 20 is advantageously comprised of metal. Though in anotherembodiment it can also be formed out of a non-metallic material, such asa carbon fiber composite material preferably with embedded carbonfibers, graphite fibers and/or fiberglass. A metal-non-metal mixture canalso be employed.

In another embodiment the flow body 20 can also be made of syntheticmaterial or synthetic materials, such as polyoxymethylene,polyformaldehyde or polyacetates. These materials typically have a highgliding quality, which is advantageous for friction in water.

The inventive rudder blade 15 with the flow body 20 is usedadvantageously in fully suspended rudders.

It is also effective if the flow body 20 is integrated in the rudderblade 15 or the flow body 20 is attached half and half for example onboth sides of the rudder blade 15.

As is evident in FIGS. 2, 3 and 4, the leading edge stringer strips 70,71 of both superposed rudder blade regions A and B facing the propeller12 are offset to one another such that the leading edge stringer strip70 of the upper rudder blade region A is offset to the port side P andthe leading edge stringer strip 71 is offset to the to the starboardside S. The reverse offsetting is also possible. The outer wall faces 15a, 15 b of the rudder blade 15 are united in an end strip 75 averted orfacing way from the propeller 12 (twisted rudder).

By the leading edge stringer strip 70, 71 of both rudder blade regions Aand B being offset to one another, so that the leading edge stringerstrip of the upper rudder blade section is offset to the port side andthe leading edge stringer strip of the lower rudder blade section isoffset to the starboard side or the leading edge stringer strip of theupper rudder blade section is offset to the starboard side and theleading edge stringer strip of the lower rudder blade section is offsetto the port side, in each case resulting in two mirror-invertedcross-sectional profiles of both rudder blade regions.

The advantage of such a rudder blade 15 designed according to theinvention having two mirror-inverted cross-sectional profiles is firstthat it prevents vapor lock and it also prevents erosion phenomena onthe rudder, occurring through cavitation in fast ships with high-loadpropellers. The special configuration of the rudder blade contributes toa drop in fuel consumption. There is an improvement in efficiency, inaddition to considerable cavitation protection. There is alsosubstantial reduction in weight.

1. A rudder for ships, comprising a rudder blade (15), which isassociated with a propeller (12) arranged on a driven propulsion axis,and a flow body (20) having a bulb-shaped or zeppelin shapedconfiguration arranged on the rudder blade (15) as an extension of thepropulsion axis in a region of the rudder blade (15), wherein the flowbody (20) includes individual sections defined by break-off lines in theflow body (20), said break-off lines comprising material weaknesses,material reductions, shear lines or perforations in the flow body (20)whereby the flow body (20) is self-destructive or self-releasing in theevent of a force, a blow, an impact or pressure on the flow body,whereby damage to the rudder blade is reduced or prevented when the flowbody (20) self-destructs or self-releases, wherein the predeterminedbreak-off lines (40) extend generally along a length or transverse to alongitudinal axis of the flow body (20).
 2. The rudder as claimed inclaim 1, wherein the predetermined break-off lines (40) are distributedin a reticulated manner over the flow body (20).
 3. The rudder asclaimed in claim 1, wherein the flow body (20) comprises a sphericalcap-shaped component (55) connected solidly or detachably to the rudderblade (15) and two individual bowl-shaped longitudinal bodies (50, 51)detachably connected by the break-off lines (40) to outer wall faces (15a, 15 b) of the rudder blade (15) and the spherical cap-shaped component(55).
 4. The rudder as claimed in claim 3, wherein the flow body (20)and the bowl-shaped longitudinal bodies (50, 51) are comprised of carbonfiber composite materials, fiber composite materials with embeddedgraphite fibers, fiberglass, a metal-non-metal mixture, or a syntheticmaterial.
 5. The rudder as claimed in claim 1, wherein the rudder blade(15) has a cross-sectional area (16) with a longitudinal middle line(LM1) that is offset at an angle α to a middle line (ML) of the flowbody (20), so that a leading edge stringer strip (70; 71) of the rudderblade (15) facing the propeller (12) is not aligned with the middle line(ML) of the flow body (20).
 6. The rudder as claimed in claim 1, whereinthe flow body (20) comprises a synthetic material.
 7. The rudder asclaimed in claim 6, wherein the synthetic material is one of the groupconsisting of polyoxymethylene, polyformaldehyde and polyacetates. 8.The rudder as claimed in claim 1, wherein the predetermined break-offlines (40) are irregular.
 9. The rudder of claim 1, wherein the flowbody (20) divides the rudder blade (15) into upper and lower areas (Aand B) each having a longitudinal middle axis line (LM1) from a frontedge thereof to a back edge thereof wherein the longitudinal middle axislines (LM1) of the upper and lower areas (A and B) of the rudder blade(15) are not aligned with a middle line (ML) of the flow body (20) andeach form an angle therewith, wherein the angle (α) between thelongitudinal middle axis line (LM1) of the upper area (A) and the middleline (ML) of the flow body (20) is different from the angle (β) betweenthe longitudinal middle axis line (LM1) of the lower area (B) and themiddle line (ML) of the flow body (20).
 10. The rudder as claimed inclaim 9, wherein first and second leading edge stringer strips (70, 71)of the upper and lower rudder blade areas (A and B) facing the propeller(12) are offset to one another such that the first leading edge stringerstrip (70) of the upper rudder blade area (A) is offset to either a portside (P) or a starboard side (S) and the second leading edge stringerstrip (71) of the lower rudder blade (B) is offset to the oppositestarboard side (S) or port side (P), whereby outer wall faces (15 a, 15b) of the rudder blade (15) are joined in an end strip (75) facing awayfrom the propeller (12).
 11. The rudder as claimed in claim 9, whereinthe upper and lower areas (A and B) have an identical profile.
 12. Therudder as claimed in claim 9, wherein the upper and lower areas (A andB) have different profiles.
 13. A rudder for ships, comprising a rudderblade (15), which is associated with a propeller (12) arranged on adriven propulsion axis, and a flow body (20) having a bulb-shaped orzeppelin shaped configuration arranged on the rudder blade (15) as anextension of the propulsion axis in a region of the rudder blade (15);wherein the flow body (20) includes individual sections defined bybreak-off lines in the flow body (20), said break-off lines comprisingmaterial weaknesses, material reductions, shear lines or perforations inthe flow body (20) whereby the flow body (20) is self-destructive orself-releasing in the event of a force, a blow, an impact or pressure onthe flow body, whereby damage to the rudder blade is reduced orprevented when the flow body (20) self-destructs or self-releases;wherein the flow body (20) divides the rudder blade (15) into upper andlower areas (A and B) each having a longitudinal middle axis line (LM1)from a front edge thereof to a back edge thereof wherein thelongitudinal middle axis lines (LM1) of the upper and lower areas (A andB) of the rudder blade (15) are not aligned with a middle line (ML) ofthe flow body (20) and each form an angle therewith, wherein the angle(α) between the longitudinal middle axis line (LM1) of the upper area(A) of the rudder blade (15) and the middle line (ML) of the flow body(20) is different from the angle (β) between the longitudinal middleaxis line (LM1) of the lower area (B) and the middle line (ML) of theflow body (20); and wherein the break-off lines (40) extend generallyalong a length or transverse to a longitudinal axis of the flow body(20).
 14. A rudder for ships, comprising a rudder blade (15), which isassociated with a propeller (12) arranged on a driven propulsion axis,and a flow body (20) having a bulb-shaped or zeppelin shapedconfiguration arranged on the rudder blade (15) as an extension of thepropulsion axis in a region of the rudder blade (15); wherein the flowbody (20) includes individual sections defined by break-off lines in theflow body (20), said break-off lines comprising material weaknesses,material reductions, shear lines or perforations in the flow body (20)whereby the flow body (20) is self-destructive or self-releasing in theevent of a force, a blow, an impact or pressure on the flow body,whereby damage to the rudder blade is reduced or prevented when the flowbody (20) self-destructs or self-releases; wherein the flow body (20)divides the rudder blade (15) into upper and lower areas (A and B) eachhaving a longitudinal middle axis line (LM1) from a front edge thereofto a back edge thereof wherein the longitudinal middle axis lines (LM1)of the upper and lower areas (A and B) of the rudder blade (15) are notaligned with a middle line (ML) of the flow body (20) and each form anangle therewith, wherein the angle (α) between the longitudinal middleaxis line (LM1) of the upper area (A) of the rudder blade (15) and themiddle line (ML) of the flow body (20) is different from the angle (β)between the longitudinal middle axis line (LM1) of the lower area (B)and the middle line (ML) of the flow body (20); and wherein thebreak-off lines (40) are distributed in a reticulated manner over theflow body (20).
 15. A rudder for ships, comprising a rudder blade (15),which is associated with a propeller (12) arranged on a drivenpropulsion axis, and a flow body (20) having a bulb-shaped or zeppelinshaped configuration arranged on the rudder blade (15) as an extensionof the propulsion axis in a region of the rudder blade (15); wherein theflow body (20) includes individual sections defined by break-off linesin the flow body (20), said break-off lines comprising materialweaknesses, material reductions, shear lines or perforations in the flowbody (20) whereby the flow body (20) is self-destructive orself-releasing in the event of a force, a blow, an impact or pressure onthe flow body, whereby damage to the rudder blade is reduced orprevented when the flow body (20) self-destructs or self-releases;wherein the flow body (20) divides the rudder blade (15) into upper andlower areas (A and B) each having a longitudinal middle axis line (LM1)from a front edge thereof to a back edge thereof wherein thelongitudinal middle axis lines (LM1) of the upper and lower areas (A andB) of the rudder blade (15) are not aligned with a middle line (ML) ofthe flow body (20) and each form an angle therewith, wherein the angle(α) between the longitudinal middle axis line (LM1) of the upper area(A) of the rudder blade (15) and the middle line (ML) of the flow body(20) is different from the angle (β) between the longitudinal middleaxis line (LM1) of the lower area (B) and the middle line (ML) of theflow body (20); and wherein the flow body (20) comprises a sphericalcap-shaped component (55) connected solidly or detachably to the rudderblade (15) and two individual bowl-shaped longitudinal bodies (50, 51)detachably connected by the break-off lines (40) to outer wall faces (15a, 15 b) of the rudder blade (15) and the spherical cap-shaped component(55).
 16. A rudder for ships, comprising a rudder blade (15), which isassociated with a propeller (12) arranged on a driven propulsion axis,and a flow body (20) having a bulb-shaped or zeppelin shapedconfiguration arranged on the rudder blade (15) as an extension of thepropulsion axis in a region of the rudder blade (15); wherein the flowbody (20) includes individual sections defined by break-off lines in theflow body (20), said break-off lines comprising material weaknesses,material reductions, shear lines or perforations in the flow body (20)whereby the flow body (20) is self-destructive or self-releasing in theevent of a force, a blow, an impact or pressure on the flow body,whereby damage to the rudder blade is reduced or prevented when the flowbody (20) self-destructs or self-releases; wherein the flow body (20)divides the rudder blade (15) into upper and lower areas (A and B) eachhaving a longitudinal middle axis line (LM1) from a front edge thereofto a back edge thereof wherein the longitudinal middle axis lines (LM1)of the upper and lower areas (A and B) of the rudder blade (15) are notaligned with a middle line (ML) of the flow body (20) and each form anangle therewith, wherein the angle (α) between the longitudinal middleaxis line (ML1) of the upper area (A) of the rudder blade (15) and themiddle line (ML) of the flow body (20) is different from the angle (β)between the longitudinal middle axis line (LM1) of the lower area (B)and the middle line (ML) of the flow body (20); and wherein thelongitudinal middle line (LM1) of the upper area A is offset at theangle α to the middle line (ML) of the flow body (20) and thelongitudinal middle line (LM1) of the lower area B is offset at theangle β to the middle line (ML) of the flow body (20), so that a leadingedge stringer strips (70; 71) upper and lower areas (A and B) of therudder blade (15) facing the propeller (12) are not aligned with themiddle line (ML) of the flow body (20).
 17. A rudder for ships,comprising a rudder blade (15), which is associated with a propeller(12) arranged on a driven propulsion axis, and a flow body (20) having abulb-shaped or zeppelin shaped configuration arranged on the rudderblade (15) as an extension of the propulsion axis in a region of therudder blade (15); wherein the flow body (20) includes individualsections defined by break-off lines in the flow body (20), saidbreak-off lines comprising material weaknesses, material reductions,shear lines or perforations in the flow body (20) whereby the flow body(20) is self-destructive or self-releasing in the event of a force, ablow, an impact or pressure on the flow body, whereby damage to therudder blade is reduced or prevented when the flow body (20)self-destructs or self-releases; wherein the flow body (20) divides therudder blade (15) into upper and lower areas (A and B) each having alongitudinal middle axis line (LM1) from a front edge thereof to a backedge thereof wherein the longitudinal middle axis lines (LM1) of theupper and lower areas (A and B) of the rudder blade (15) are not alignedwith a middle line (ML) of the flow body (20) and each form an angletherewith, wherein the angle (α) between the longitudinal middle axisline (LM1) of the upper area (A) of the rudder blade (15) and the middleline (ML) of the flow body (20) is different from the angle (β) betweenthe longitudinal middle axis line (LM1) of the lower area (B) and themiddle line (ML) of the flow body (20); and wherein first and secondleading edge stringer strips (70, 71) of the upper and lower rudderblade areas (A and B) facing the propeller (12) are offset to oneanother such that the first leading edge stringer strip (70) of theupper rudder blade area (A) is offset to either a port side (P) or astarboard side (S) and the second leading edge stringer strip (71) ofthe lower rudder blade (B) is offset to the opposite starboard side (S)or port side (P), whereby outer wall faces (15 a, 15 b) of the rudderblade (15) are joined in an end strip (75) facing away from thepropeller (12).
 18. A rudder for ships, comprising a rudder blade (15),which is associated with a propeller (12) arranged on a drivenpropulsion axis, and a flow body (20) having a bulb-shaped or zeppelinshaped configuration arranged on the rudder blade (15) as an extensionof the propulsion axis in a region of the rudder blade (15); wherein theflow body (20) includes individual sections defined by break-off linesin the flow body (20), said break-off lines comprising materialweaknesses, material reductions, shear lines or perforations in the flowbody (20) whereby the flow body (20) is self-destructive orself-releasing in the event of a force, a blow, an impact or pressure onthe flow body, whereby damage to the rudder blade is reduced orprevented when the flow body (20) self-destructs or self-releases;wherein the flow body (20) divides the rudder blade (15) into upper andlower areas (A and B) each having a longitudinal middle axis line (LM1)from a front edge thereof to a back edge thereof wherein thelongitudinal middle axis lines (LM1) of the upper and lower areas (A andB) of the rudder blade (15) are not aligned with a middle line (ML) ofthe flow body (20) and each form an angle therewith, wherein the angle(α) between the longitudinal middle axis line (LM1) of the upper area(A) of the rudder blade (15) and the middle line (ML) of the flow body(20) is different from the angle (β) between the longitudinal middleaxis line (LM1) of the lower area (B) and the middle line (ML) of theflow body (20); wherein the break-off lines (40) extend generally alonga length or transverse to a longitudinal axis of the flow body (20); andwherein the break-off lines (40) are irregular.
 19. A rudder for ships,comprising a rudder blade (15), which is associated with a propeller(12) arranged on a driven propulsion axis, and a flow body (20) having abulb-shaped or zeppelin shaped configuration arranged on the rudderblade (15) as an extension of the propulsion axis in a region of therudder blade (15); wherein the flow body (20) includes individualsections defined by break-off lines in the flow body (20), saidbreak-off lines comprising material weaknesses, material reductions,shear lines or perforations in the flow body (20) whereby the flow body(20) is self-destructive or self-releasing in the event of a force, ablow, an impact or pressure on the flow body, whereby damage to therudder blade is reduced or prevented when the flow body (20) selfdestructs or self-releases; wherein the flow body (20) divides therudder blade (15) into upper and lower areas (A and B) each having alongitudinal middle axis line (LM1) from a front edge thereof to a backedge thereof wherein the longitudinal middle axis lines (LM1) of theupper and lower areas (A and B) of the rudder blade (15) are not alignedwith a middle line (ML) of the flow body (20) and each form an angletherewith, wherein the angle (α) between the longitudinal middle axisline (LM1) of the upper area (A) of the rudder blade (15) and the middleline (ML) of the flow body (20) is different from the angle (β) betweenthe longitudinal middle axis line (LM1) of the lower area (B) and themiddle line (ML) of the flow body (20); and wherein the areas (A and B)have identical profiles.
 20. A rudder for ships, comprising a rudderblade (15), which is associated with a propeller (12) arranged on adriven propulsion axis, and a flow body (20) having a bulb-shaped orzeppelin shaped configuration arranged on the rudder blade (15) as anextension of the propulsion axis in a region of the rudder blade (15);wherein the flow body (20) includes individual sections defined bybreak-off lines in the flow body (20), said break-off lines comprisingmaterial weaknesses, material reductions, shear lines or perforations inthe flow body (20) whereby the flow body (20) is self-destructive orself-releasing in the event of a force, a blow, an impact or pressure onthe flow body, whereby damage to the rudder blade is reduced orprevented when the flow body (20) self-destructs or self-releases;wherein the flow body (20) divides the rudder blade (15) into upper andlower areas (A and B) each having a longitudinal middle axis line (LM1)from a front edge thereof to a back edge thereof wherein thelongitudinal middle axis lines (LM1) of the upper and lower areas (A andB) of the rudder blade (15) are not aligned with a middle line (ML) ofthe flow body (20) and each form an angle therewith, wherein the angle(α) between the longitudinal middle axis line (LM1) of the upper areas(A) of the rudder blade (15) and the middle line (ML) of the flow body(20) is different from the angle (β) between the longitudinal middleaxis line (LM1) of the lower area (B) and the middle line (ML) of theflow body (20); and wherein the upper and lower areas (A and B) havedifferent profiles.